How does ArcGIS Desktop (and probably most other WMS clients) request data from supported servers? If we take their own sample server as an example, I can understand how Desktop connects to the server, knows which layers are on it etc, but when I add the service to Desktop and it starts showing map images, how does it get those images? I can't find anything in the XML file that points to any kind of source for these images, although it has SRS, boundingbox and all the metadata about the maps.
What am I missing here?
EDIT: To clarify, I have a (homemade) server application, which creates and sends the following XML file upon receiving a GetCapabilities request:
<?xml version="1.0" encoding="UTF-8"?> <WMS_Capabilities xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <Service> <Name>Name</Name> <Title>EivaTMS</Title> <Abstract>Something clever about this WMS</Abstract> <Capability> <Layer> <Title>kraken.db</Title> <Name>Name</Name> <Abstract/> <SRS>OSGEO:41001</SRS> <Profile>NaviPacLocal</Profile> <Format>image/png</Format> <BoundingBox> <xmin>140</xmin> <xmax>140</xmax> <ymin>80</ymin> <ymax>80</ymax> <zmin>0</zmin> <zmax>0</zmax> </BoundingBox> <MapSize>256</MapSize> <CellSize>3</CellSize> <MaxLevel>32</MaxLevel> </Layer> </Capability> </Service> </WMS_Capabilities>
I'm well away that this XML doesn't stand a chance when comparing it to the WMS specification but this is due to it being used for my own client at some point, but now I'm in need of being able to use it with ArcGIS. Now, ArcGIS Explorer is obviously able to send a GetCapabilities request (some_url?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetCapabilities) and it's able to see 'kraken.db' which I assume is because of the 'Layer' tag it's surrounded by. I can see my server receives the request and that it sends the XML back to ArcGIS, which gives me this window where I have to choose a service:
But when I try to add it, I get a "Unable to add service(s)" error. This isn't strange since my XML lacks a lot of information, but I have difficulties finding out exactly what kind of information ArcGIS Explorer needs in this situation.